Hello! Is there any way how to pump out water from lake or even oceans?
Do you mean drain the lake or ocean, or just get water from it?
Acquire water
Buildcraft pump with default settings will generate water from the lake or ocean without actually removing any water. Put 1-4 Redstone Engines directly contacting it and supply them with a redstone signal to power it.
If you just want to acquire water, the easiest method is putting an Aqueous Accumulator anywhere you want with two water source blocks directly adjacent to it, and then pipe water out of another side.
Drain water
If you want to drain water and replace the water with stone, use the Ender-Thermic Pump.
If you want to drain the water, leaving empty bodies of water like the following image, use the Buildcraft pump with the following config changes.
Go to the config directory of your modpack.
Locate: ChickenChunksCore.cfg and find this line:
Change "false" to "true" without quotes.
Locate: main.cfg in the buildcraft folder
Change "false" to "true" without quotes.
NOTE: The Buildcraft pump has an approximate range of 64x64 and will leave an ugly mess of broken-like water at the end of it's range if you make these changes. I recommend you build a dam like the picture so you can drain lakes and rivers nicely. Ensure that the dam is built from the surface to the ocean floor, to completely separate the water.